@conference {Alexander2016, title = {Development of 3D Slicer Based Film Dosimetry Analysis}, booktitle = {IC3DDose (9th International Conference on 3D Radiation Dosimetry)}, volume = {847}, year = {2016}, month = {10/2016}, publisher = {IOP Science}, organization = {IOP Science}, address = {Houston, TX, USA}, abstract = {

Radiochromic film dosimetry has been widely adopted in the clinic as it is a convenient option for dose measurement and verification. Film dosimetry analysis is typically performed using expensive commercial software, or custom made scripts in Matlab. However, common clinical film analysis software is not transparent regarding what corrections/optimizations are running behind the scenes. An extension to the open-source medical imaging platform 3D Slicer has been designed and implemented in our centre for film dosimetry analysis. This extension enables importing treatment planning system dose and film imaging data, film calibration, registration, and comparison of 2D dose distributions, enabling greater accessibility to film analysis and higher reliability.

}, author = {Kevin Alexander and Alec Robinson and Csaba Pinter and Gabor Fichtinger and John Schreiner} } @conference {Alexander2015, title = {3D Slicer Gel Dosimetry Analysis: Validation of the Calibration Process}, booktitle = {World Congress on Medical Physics and Biomedical Engineering, June 7-12, 2015, Toronto, Canada}, volume = {51}, year = {2015}, month = {06/2015}, pages = {521-524}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, abstract = {

An extension tailored to dose data processing and analysis has been developed in the open source imaging application 3D Slicer to aid in routine clinical use of gel dosim-etry. This extension allows for registration, calibration, and comparison of 3D gel dosimeter data (imaged using an optical CT scanner) to treatment planning data. In this work, we present the accuracy and reproducibility of the gel dosimeter calibration component of the 3D Slicer extension. We examine the consistency of the calibration curves for a range of electron beam irradiations, and the inter-user variability of the gel dosimeter calibration process.

}, doi = {10.1007/978-3-319-19387-8_128}, url = {http://link.springer.com/chapter/10.1007\%2F978-3-319-19387-8_128}, author = {Kevin Alexander and Csaba Pinter and Jennifer Andrea and Gabor Fichtinger and John Schreiner} } @conference {Schumacher2015, title = {3D-printed surface mould applicator for high-dose-rate brachytherapy}, booktitle = {SPIE Medical Imaging 2015}, volume = {9415}, year = {2015}, abstract = {

ABSTRACT

PURPOSE: In contemporary high-dose-rate brachytherapy treatment of superficial tumors, catheters are placed in a wax mould. The creation of current wax models is a difficult and time consuming proces.The irradiation plan can only be computed post-construction and requires a second CT scan. In case no satisfactory dose plan can be created, the mould is discarded and the process is repeated. The objective of this work was to develop an automated method to replace suboptimal wax moulding. METHODS: We developed a method to design and manufacture moulds that guarantee to yield satisfactory dosimetry. A 3D-printed mould with channels for the catheters designed from the patient{\textquoteright}s CT and mounted on a patient-specific thermoplastic mesh mask. The mould planner was implemented as an open-source module in the 3D Slicer platform. RESULTS: Series of test moulds were created to accommodate standard brachytherapy catheters of 1.70mm diameter. A calibration object was used to conclude that tunnels with a diameter of 2.25mm, minimum 12mm radius of curvature, and 1.0mm open channel gave the best fit for this printer/catheter combination. Moulds were created from the CT scan of thermoplastic mesh masks of actual patients. The patient-specific moulds have been visually verified to fit on the thermoplastic meshes. CONCLUSION: The masks were visually shown to fit onto the thermoplastic meshes, next the resulting dosimetry will have to be compared with treatment plans and dosimetry achieved with conventional wax moulds in order to validate our 3D printed moulds.

}, author = {Mark Schumacher and Andras Lasso and Ian Cumming and Adam Rankin and Conrad Falkson and John Schreiner and C.P. Joshi and Gabor Fichtinger} } @article {Cumming2014, title = {3D Printed Patient-Specific Surface Mould Applicators for Brachytherapy Treatment of Superficial Lesions}, volume = {41 (abstract in Medical Physics)}, number = {222}, year = {2014}, month = {06/2014}, abstract = {

Purpose:
Evaluate the feasibility of constructing 3D-printed patient-specific surface mould applicators for HDR brachytherapy treatment of superficial lesions.

Methods:
We propose using computer-aided design software to create 3D printed surface mould applicators for brachytherapy. A mould generation module was developed in the open-source 3D Slicer (www.slicer.org) medical image analysis platform. The system extracts the skin surface from CT images, and generates smooth catheter paths over the region of interest based on user-defined start and end points at a specified stand-off distance from the skin surface. The catheter paths are radially extended to create catheter channels that are sufficiently wide to ensure smooth insertion of catheters for a safe source travel. An outer mould surface is generated to encompass the channels. The mould is also equipped with fiducial markers to ensure its reproducible placement.

A surface mould applicator with eight parallel catheter channels of 4mm diameters was fabricated for the nose region of a head phantom; flexible plastic catheters of 2mm diameter were threaded through these channels maintaining 10mm catheter separations and a 5mm stand-off distance from the skin surface. The apparatus yielded 3mm thickness of mould material between channels and the skin. The mould design was exported as a stereolithography file to a Dimension SST1200es 3D printer and printed using ABS Plus plastic material.

Results:
The applicator closely matched its design and was found to be sufficiently rigid without deformation during repeated application on the head phantom. Catheters were easily threaded into channels carved along catheter paths. Further tests are required to evaluate feasibility of channel diameters smaller than 4mm.

Conclusion:
Construction of 3D-printed mould applicators show promise for use in patient specific brachytherapy of superficial lesions. Further evaluation of 3D printing techniques and materials is required for constructing sufficiently thin, rigid and durable surface moulds suitable for clinical deployment.

}, doi = {http://dx.doi.org/10.1118/1.4888333}, author = {Ian Cumming and C.P. Joshi and Andras Lasso and Adam Rankin and Conrad Falkson and John Schreiner and Gabor Fichtinger} } @conference {Alexander2014, title = {Implementation of an efficient workflow process for gel dosimetry using 3D Slicer}, booktitle = {IC3DDose}, year = {2014}, abstract = {

One challenge in gel dosimetry is the manipulation and analysis of complex data sets from different systems. In this paper, we describe a simple and fast gel dosimetry analysis tool for radiation therapy dose deliveries. Using the open source medical imaging software 3D Slicer, an extension was designed and implemented for the purpose of importing treatment planning system dose, CT imaging from simulation and at treatment, and optical CT gel dosimeter data. The extension also allows for calibration of gel dosimeter data, registration, and comparison of 3D dose distributions. The development of an open source gel dosimetry processing environment may help adoption of gels in the clinic.

}, author = {Kevin Alexander and Csaba Pinter and Jennifer Andrea and Gabor Fichtinger and John Schreiner} } @article {Lasso2014b, title = {Running Matlab functions in 3D Slicer using MatlabBridge}, year = {2014}, month = {03/2014}, pages = {78}, address = {Toronto, ON, Canada, March 24-25, 2014}, url = {http://www.imno.ca/sites/default/files/2014Proceedings.pdf}, author = {Andras Lasso and Kevin Alexander and Christopher Jechel and Kevin Wang and John Schreiner and Gabor Fichtinger} } @article {Andrea2014a, title = {Slicelet implementation for gel dosimetry analysis}, year = {2014}, month = {03/2014}, pages = {63}, address = {Toronto, Canada}, url = {http://www.imno.ca/sites/default/files/2014Proceedings.pdf}, author = {Jennifer Andrea and Mattea Welch and Csaba Pinter and Kevin Alexander and John Schreiner and Gabor Fichtinger} } @article {Pompeu-Robinson2011, title = {Immobilization and Catheter Guidance for Breast Brachytherapy}, journal = {International Journal of Computer Assisted Radiology and Surgery}, volume = {Online First}, year = {2011}, month = {05/2011}, abstract = {

Purpose: Brachytherapy is an important mode of breast cancer treatment; however, improvements in both treatment planning and delivery are needed. In order to meet these specific needs, integration of pre-operative imaging, supplemented by computerized surgical planning and mathematical optimization were used to develop and test an intra-operative immobilization and catheter guidance system. Method: A custom template specific to each patient with optimally placed guide holes for catheter insertion was designed and fabricated. Creation of the template is based on a virtual reality reconstruction of the patient{\textquoteright}s anatomy from computed tomography imaging. The template fits on the patient{\textquoteright}s breast, immobilizing the soft tissue, and provides pre-planned catheter insertion holes for guidance to the tumor site. Agar-based phantom and target models were used for quantitative validation of the template by ascertaining the precision and accuracy of the templates. Results: Tests were performed on agar-based tissue models using computed tomography imaging for template planning and validation. Planned catheter tracks were compared to post-insertion image data and distance measurements from target location were used to create an error measure. Initial results yielded an average error of 4.5 mm. Once the workflow and template design were improved, an average error of 2.6 mm was observed, bringing the error close to a clinically acceptable range. Conclusion: Use of a patient-specific template for breast brachytherapy is feasible and may improve the procedure accuracy and outcome.

}, keywords = {Brachytherapy, Breast cancer, Guidance, Immobilization, Radiotherapy}, doi = {DOI 10.1007/s11548-011-0600-6}, author = {Alexandra M. Pompeu-Robinson and M. Kunz and Conrad Falkson and John Schreiner and C.P. Joshi and Gabor Fichtinger} }